Movement in the Atmosphere
Air can move in the atmosphere and close to the ground, which can have an affect on aircraft during its flight.
Turbulence: is caused when an airplane flies through waves of air that are irregular or violent, which cause the aircraft to bounce around yawing, pitching, or rolling. Turbulence is associated with fronts, wind shear, thunderstorms, etc.
Laminar flow: type of fluid (gas or liquid) flow in which the fluid travels smoothly or in regular paths
Mechanical turbulence: Friction between the air and the ground, especially irregular terrain and man-made obstacles, causes eddies and therefore turbulence in the lower levels. Air breaks into a series of eddies (whirlpools of air).
Image Source: https://www.futuresky-safety.eu/wake-vortex-coordination/
Image Source: https://www.weather.gov/source/zhu/ZHU_Training_Page/turbulence_stuff/turbulence/turbulence.htm
Air is also lifted and moved around in different ways.
Turbulent lift: when air mass passes up and over chaotic low altitude air
Convective lift: when an air mass is heated by its surroundings, thereby becoming less dense and rising to higher elevations
Orographic Lift: Air blowing against range of hills or mountains is forced to rise
Frontal Lift: warmer air moves up and over an edge of a cold mass below it
Convergent lift: when air near the surface flows together and is pushed upward when it is squeezed together
Image Source: https://kids.britannica.com/students/assembly/view/53902